Two-dimensional and Doppler echocardiographic examination were obtained in 31 patients both immediately and 2 to 5 months(mean3.1±1.8) after balloon dilation. Mitral valve area by planimetry immediately after valvuloplasty measured 1.8±0.3cm² and 1.7±0.3cm² at 2-5 months follow-up, but the difference was satistically insignificant. More than 15% decrease of the mitral valve area at follow-up was noticed in 10 patients(32%), but the valve area at follow-up was >1.5cm² in all patients. Left atrial size(antero-posterior diameter) and volume by 2-dimensional echocardiography decreased more remarkably from 4.4±0.7cm, 82±42cm³ immediatly after vavuloplasty to 4.2±0.7cm, 68±26cm² at follow-up respectively but there was no statistical significance. Mitral regurgitation graded by pulsed Doppler ultrasound decreased from 1.6±0.7 immediatly after valvuloplasty to 1.3±0.5(p<0.09) at follow-up, but there was no significant change in peak E velocity, EF slope, fractional shortening and ejection fraction. Symptomatic improvement at follow-up occured in all but one patient. Thus, 2 to 5 months after balloon mitral valvuloplasty there was no significantly after valvuloplasty decreased slightly at follow-up.